1 Samuel 17:34-36

17:34 David replied to Saul, “Your servant has been a shepherd for his father’s flock. Whenever a lion or bear would come and carry off a sheep from the flock, 17:35 I would go out after it, strike it down, and rescue the sheep from its mouth. If it rose up against me, I would grab it by its jaw, strike it, and kill it. 17:36 Your servant has struck down both the lion and the bear. This uncircumcised Philistine will be just like one of them. For he has defied the armies of the living God!”

1 Samuel 17:50

17:50 David prevailed over the Philistine with just the sling and the stone. He struck down the Philistine and killed him. David did not even have a sword in his hand.